The effect of coil temperature 572～648 ℃ and cold rolling reduction 65%~75% on properties of the low carbon   aluminum   killed   steel   SPHC(/%:0.04C

0.03Si

0. 14Mn

0.027Al)annealed   property   at   700   ℃   has   been   studied. The results  show that at the  same cold rolling reduction

with the increase of coiling temperature

the  strength of steel basically presents a downward trend

the elongation relatively increases

and the n and r values basically show a downward trend;  at  the  same  coiling  temperature

with  the  increase  of cold  rolling  reduction

the  strength  basically  presents  a  downward trend

the elongation first increases and then decreases

and the n and r values basically show first increases and then decreases downward trend. By comparison

the best performance of 3 mm SPHC steel plate annealed at 700 ℃ can be obtained by  hot  rolling  coiling  at  620  ℃ and  cold  rolling  deformation  70%

that  is  tensile  strength  286  MPa

yield  strength 210  MPa

elongation 43%

n-value 0.27

r-value 1.52.